Table 1.

Mean fish size for each different age group for fish in the open field test.

Fish age	Mean fish size (cm)	SD	SEM	Min (cm)	Max (cm)	Number
6 weeks	1.7	0.23	0.058	1.2	2.0	16
9 weeks	2.1	0.22	0.056	1.8	2.6	16
12 weeks	2.2	0.27	0.068	1.9	2.8	16
15 weeks	2.3	0.27	0.066	1.9	2.8	14
18 weeks	2.5	0.22	0.059	2.1	2.8	14
21 weeks	2.6	0.21	0.056	2.2	3.0	14
24 weeks	2.7	0.20	0.051	2.4	3.1	14

Minimal and maximal length, standard deviation (SD) and standard error of the mean (SEM) of fish per age group and the number of fish measured. The length of the fish per age group was used to determine the size of the center zone.